Various types of leg and foot prosthetic devices are known in the art. These devices include various forms of a rigid tubular lower leg pylon attached to an energy absorbing prosthetic foot. An adjustable angular connection can be made between the bottom of the pylon and the energy absorbing foot as disclosed in U.S. Pat. No. 4,969,911 to Greene, assigned to United State Manufacturing Company, the assignee of this application.
An alternative more flexible prosthetic leg and foot comprises a long, flat bar that forms a shin portion of the lower leg prosthesis. The lower portion of the bar is curved forward to form a foot section and a separate adjustable heel section in the form of a curved bar attaches to a lower rear portion of the shin forming bar. The foot and heel portions of the prosthesis provide spring-like members that flex when pressure is applied in order to simulate a somewhat natural walking gait. Various configurations of heel sections can be added to adjust energy absorbing characteristics. During use, the heel compresses and the foot and the shin bar flex. The flexible bar is made from a carbon filament and an epoxy resin composite material that provides the flexibility. This prosthetic foot and leg combination is sold under the trademark Flex Foot and is disclosed in U.S. Pat. Nos. 4,547,913 and 4,822,363 to Phillips, assigned to Flex Foot, Inc.
A principal use of the Flex Foot device is for a lower leg prosthesis for below-knee amputations. Although its flexibility may be desirable, the Flex Foot device lacks sufficient adjustability for making alignment changes that can be critical in certain functioning of a prosthesis.
It can also be desirable to provide certain critical angular adjustments for alignment of a lower leg prosthesis for an above-knee amputation. For instance, it may be desirable to provide a flexible lower leg prosthesis for an above-knee amputation when the lower leg prosthesis is used with a prosthetic knee joint. Further, certain prosthetic devices are used with a hip disarticulation joint. In these instances, alignment with the hip disarticulation joint and sufficient flexibility of the overall prosthesis to assist in knee flexion are desirable.
The present invention provides a prosthetic limb and alignment adapter having controlled flexibility and means for adjusting the alignment of the flexible component in various selected orientations depending upon the end use of the prosthetic device. One embodiment provides a flexible lower leg prosthesis with improved adjustability for alignment purposes. Another embodiment is adaptable to above-knee amputations, and more particularly, to hip disarticulation patients by providing improved flexibility for the knee joint function, together with an adjustable means of alignment that enables the flexibility of the overall prosthetic device to be properly controlled during use.